I own a 2005 Honda TRX250EX, Me and 8 other guys will be traveling to UTAH this upcoming year. What do I need to do to ride in the higher altitude?
I heard something about jetting? Is there a website to explain this to me? Or should I have the Honda do it for me when I'm ready?
Any answers would be appreciated.
Thank you
Chris

 

I can be riding one day at below sea level, and in the high Sierra the next. Our typical mountain ride starts in the valley at 4,000' and goes up to over 10,000'........all in one afternoon! It would be absolutely ridiculous to try to rejet so often.

So, what I do is drill eight 1" holes in the airbox lid and install those round UNI vents. When I am at low altitude, I just leave them all taped over with duct tape. Then, as I ascend in altitude I uncover more and more of them, until at around 9,000', I just pull the lid off altogether. Then as I descend, I replace the lid and tape in reverse order. (It is important that you replace the tape, or you will run LEAN at low altitude and may damage your engine!) (Note that on the Rancher I use the TPI valve (http://www.thunderproducts.com/tpi_valve.htm), but they are to deep to fit into the Recon/250EX airbox, so I just use the holes method on those.)

This is really a method of rejetting! If you rejet you are decreasing the amount of fuel. All my method does is increase the amount of air, to compensate for having less oxygen......in the end it does the same thing.

This method works absolutely great! It is cheap, and it is easy to do............